Re: [PATCH v1 03/11] cpufreq: tegra20: Remove EMC clock usage

Viresh Kumar
2018-05-18T01:54:56Z

On 17-05-18, 21:00, Dmitry Osipenko wrote:
> The EMC driver has been gone 4 years ago, since the commit a7cbe92cef27
> ("ARM: tegra: remove tegra EMC scaling driver"). Remove the EMC clock
> usage as it does nothing. We may consider re-implementing the EMC scaling
> later, probably using PM Memory Bandwidth QoS API.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/cpufreq/tegra20-cpufreq.c | 22 ----------------------
> 1 file changed, 22 deletions(-)
>
> diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
> index dd8a76a64a8e..693f9067ba8a 100644
> --- a/drivers/cpufreq/tegra20-cpufreq.c
> +++ b/drivers/cpufreq/tegra20-cpufreq.c
> @@ -44,7 +44,6 @@ static struct cpufreq_frequency_table freq_table[] = {
> static struct clk *cpu_clk;
> static struct clk *pll_x_clk;
> static struct clk *pll_p_clk;
> -static struct clk *emc_clk;
> static bool pll_x_prepared;
>
> static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy,
> @@ -95,17 +94,6 @@ static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
> unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000;
> int ret = 0;
>
> - /*
> - * Vote on memory bus frequency based on cpu frequency
> - * This sets the minimum frequency, display or avp may request higher
> - */
> - if (rate >= 816000)
> - clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
> - else if (rate >= 456000)
> - clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
> - else
> - clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */
> -
> /*
> * target freq == pll_p, don't need to take extra reference to pll_x_clk
> * as it isn't used anymore.
> @@ -141,14 +129,12 @@ static int tegra_cpu_init(struct cpufreq_policy *policy)
> if (policy->cpu >= NUM_CPUS)
> return -EINVAL;
>
> - clk_prepare_enable(emc_clk);
> clk_prepare_enable(cpu_clk);
>
> /* FIXME: what's the actual transition time? */
> ret = cpufreq_generic_init(policy, freq_table, 300 * 1000);
> if (ret) {
> clk_disable_unprepare(cpu_clk);
> - clk_disable_unprepare(emc_clk);
> return ret;
> }
>
> @@ -160,7 +146,6 @@ static int tegra_cpu_init(struct cpufreq_policy *policy)
> static int tegra_cpu_exit(struct cpufreq_policy *policy)
> {
> clk_disable_unprepare(cpu_clk);
> - clk_disable_unprepare(emc_clk);
> return 0;
> }
>
> @@ -192,19 +177,12 @@ static int __init tegra_cpufreq_init(void)
> if (IS_ERR(pll_p_clk))
> return PTR_ERR(pll_p_clk);
>
> - emc_clk = clk_get_sys("cpu", "emc");
> - if (IS_ERR(emc_clk)) {
> - clk_put(cpu_clk);
> - return PTR_ERR(emc_clk);
> - }
> -
> return cpufreq_register_driver(&tegra_cpufreq_driver);
> }
>
> static void __exit tegra_cpufreq_exit(void)
> {
> cpufreq_unregister_driver(&tegra_cpufreq_driver);
> - clk_put(emc_clk);
> clk_put(cpu_clk);
> }

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

--
viresh